Sludge, made up of solids and liquid, is formed as a by-product of many processes used in a wide range of industries (e.g. mining, food processing, manufacturing, sewage treatment, etc.) Sludge may be treated at the same location where it is created or it may be transported to an alternative location for treatment or disposal. Environmental considerations and/or specialist sludge processing requirements often determine where and how the sludge is treated and disposed of.
One example of sludge that requires treatment is in the drilling industry, where drill muds are created as a by-product during and after the drilling process. Drill mud is often considered contaminated waste and must be processed prior to being re-integrated with the environment. In particular, this processing may comprise the removal of water in the drill mud.
Ordinary methods of separation, such as cyclonic separation, filtration, membranes or screens, are generally not suited for processing of drill mud to remove water. This is usually due to additives contained in the drill mud or the fine particle size of the sediments in the removed earth which, together with the water, act to block filters and resist separation. Thus, current methods of water removal for drill mud are mainly directed to settling processes, whereby the mud is stored in shallow ponds and water is allowed to evaporate naturally into the atmosphere.
Such methods require the construction of specialist environmental containment dams and specialist treatment facilities for any non-evaporative separation, or large areas of land for natural settling. These methods can be expensive due to the cost of constructing the pond, maintaining it during its lifetime and then reinstating the land to its original condition after the useful life of the pond. Ponds, in particular, face a further issue, whereby evaporation of liquid from the pond can increase the concentration of chemicals in the pond. Thus, for example, a pond (and the sludge contained therein) may be deemed to be at acceptable chemical concentration levels initially, but over time these levels may increase above acceptable levels due to evaporation. Such chemical concentration levels can have an adverse impact on the surrounding environment.
The above references to the background art do not constitute an admission that the art forms part of the common general knowledge of a person of ordinary skill in the art. The above references are also not intended to limit the application of the apparatus and process as disclosed herein.